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  <title>Document</title>
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<body>
  <script>
    // var 
    // function

    // 函数不调用 不会执行
    function getSum() {
      //  函数盛饭的代码  封装
      console.log(123123)
      console.log(456456)
    }

    getSum()
  </script>
</body>
</html>